RE: CASE WHEN EXISTS Problem

[Tom E Stieger <testieger@xxxxxxxxxxxx>]

Paul-

Thanks for the suggestion.  I'm not sure if I want to fit that logic into my huge casse statement.  I think I will use the count function instead.  Something like this seems to work:

SELECT
CASE 	WHEN (SELECT count(1) FROM SYSIBM.SYSDUMMY1) >= 1 
	THEN 'I am awesome' 
	ELSE 'The computer has won' END
FROM SYSIBM.SYSDUMMY1

I still am not sure why the EXISTS predicate doesn't seem to work.

-Tom 

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Morgan, Paul
Sent: Friday, March 18, 2011 12:45 PM
To: midrange-l@xxxxxxxxxxxx
Subject: RE: CASE WHEN EXISTS Problem

Tom,

Use IFNULL instead of CASE?

SELECT IFNULL( ( SELECT 'I am awesome'                              
                   FROM SYSIBM/SYSDUMMY1                            
                  WHERE EXISTS( SELECT 1 FROM SYSIBM/SYSDUMMY1      
                                 UNION                              
                                SELECT 2 FROM SYSIBM/SYSDUMMY1 ) ), 
               'The computer has won')                              
FROM SYSIBM/SYSDUMMY1                                               

Paul Morgan
 
Principal Programmer Analyst
IT Supply Chain/Replenishment

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Tom E Stieger
Sent: Friday, March 18, 2011 3:13 PM
To: 'Midrange Systems Technical Discussion'
Subject: SQL: CASE WHEN EXISTS Problem

I have an SQL view that is basically doing the following, in addition to a bunch of other stuff:

SELECT
CASE 	WHEN (SELECT 1 FROM SYSIBM.SYSDUMMY1) IS NOT NULL 
	THEN 'I am awesome' 
	ELSE 'The computer has won' END
FROM SYSIBM.SYSDUMMY1

This was working fine until the subselect ended up being 2 rows such as this:

SELECT
CASE 	WHEN (SELECT 1 FROM SYSIBM.SYSDUMMY1
		UNION SELECT 2 FROM SYSIBM.SYSDUMMY1 ) IS NOT NULL 
	THEN 'I am awesome' 
	ELSE 'The computer has won' END
FROM SYSIBM.SYSDUMMY1

This gives the following Message: [SQL0811] Result of SELECT more than one row.

It looks like I should be able to use an EXISTS predicate, but I can't seem to get that to work either.

SELECT
CASE 	WHEN EXISTS (SELECT 1 FROM SYSIBM.SYSDUMMY1) 
	THEN 'I am awesome' 
	ELSE 'The computer has won' END
FROM SYSIBM.SYSDUMMY1

This gives the follwing Message: [SQL0104] Token EXISTS was not valid. Valid tokens: <IDENTIFIER> <INTEGER> <CHARSTRING> <GRAPHSTRING>

Using IN didn't work either, giving the following Message: [SQL0115] Comparison operator IN not valid.

I'm not quite sure what else to try, any help would be appreciated.  Thanks.

-Tom Stieger
California Fine Wire
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